A new book title from a national publisher centers around a Southern Quaker family. Since most Quakers were anti-slavery, would there have been any Southern Quakers? Or new Quaker congregations in the 20th century?

Nearly a year late in replying to this post, but yes, there was a historic Quaker community in the Carolinas (esp. NC). Guilford College is a remnant of that community, but most of the community relocated to Ohio in the decades just before the Civil War, as they could not economically compete with the slaveholding plantations. There remains a reasonable sized community in North Carolina and a much smaller one in South Carolina.

While I am not a Quaker myself, I am a Southerner, and there indeed are (and were!) Southern Quakers. In fact my Southern Quakers lived in the northern part of North Carolina during the 18th century. I don't know for sure what their opinion on slavery was, but given their Quaker faith I imagine they were against it!